Romex Software Forum

support wrote:

kevindd992002 wrote:I think I get what you mean. So for the same example you stated above, what if you copy a 5GB file in that same RAMDisk? If I understand correctly, that won't be possible since you just created a 4GB RAMDisk even though you have DMM enabled, right? So if you look at it practically, you are setting the limit of the RAMDisk to 4GB but it will only allocate memory "when needed" and "up to 4GB only", correct?

Yes, exactly.

kevindd992002 wrote:so every time I use an image file the features of DMM won't have any effect even though the settings of that image file sets DMM to be enabled? Won't it release memory allocation if not needed?

Well, the program is still able to release memory even when the image file enabled. (Win7/2008R2 or newer, NTFS file system).

Ok, so what were you saying earlier that DMM won't take effect if we use the image file? Can you please expound this. Thanks.

When loading an image file to the ramdisk, program have to allocate enough memory to hold the data. So, after the whole image file is loaded to the ramdisk, it seems that full-scale memory has been allocated.

support wrote:When loading an image file to the ramdisk, program have to allocate enough memory to hold the data. So, after the whole image file is loaded to the ramdisk, it seems that full-scale memory has been allocated.

But after a few minutes it will release the unused memory allocation?

kevindd992002 wrote:But after a few minutes it will release the unused memory allocation?

It happens only when you delete a file. The memory holding this file may be released.

support wrote:

kevindd992002 wrote:But after a few minutes it will release the unused memory allocation?

It happens only when you delete a file. The memory holding this file may be released.

Can you give me a concrete example of this from the time the program loads the image file at startup up to the time you delete a file and it will automatically release the memory allocation?

What I understand is, for example, I have a 512MB RAMDisk that has only 128MB worth of contents (so the memory allocation is only around 128MB). During shutdown it will still save a 512MB image file if I use plain image, right? And then when it loads that same image file during startup it will allocate the whole 512MB but only has actually 128MB contents still, right? And when I delete, let's say, a 1MB file it will release the unused memory allocation and will be only around 127MB?

kevindd992002 wrote:During shutdown it will still save a 512MB image file if I use plain image, right? And then when it loads that same image file during startup it will allocate the whole 512MB but only has actually 128MB contents still, right?

Yes.

kevindd992002 wrote:And when I delete, let's say, a 1MB file it will release the unused memory allocation and will be only around 127MB?

No. After the whole image file is loaded to the ramdisk. The program treats all data used. When you delete a 1MB file, it only releases 1MB memory (Here is just for simplicity. Actually the memory release mechanism is quite complicated and here 1MB memory may not be released.)

support wrote:

kevindd992002 wrote:During shutdown it will still save a 512MB image file if I use plain image, right? And then when it loads that same image file during startup it will allocate the whole 512MB but only has actually 128MB contents still, right?

Yes.

kevindd992002 wrote:And when I delete, let's say, a 1MB file it will release the unused memory allocation and will be only around 127MB?

No. After the whole image file is loaded to the ramdisk. The program treats all data used. When you delete a 1MB file, it only releases 1MB memory (Here is just for simplicity. Actually the memory release mechanism is quite complicated and here 1MB memory may not be released.)

Oh ok. So effectively DMM is not working properly when using an image file then? Better to not use it after all? Or is there still advantage of me using it with an image file?

There are two ways to use DMM with image file:
1. Use the "Delay Load" option.
or 2. Use the "Smart Image"

support wrote:There are two ways to use DMM with image file:
1. Use the "Delay Load" option.
or 2. Use the "Smart Image"

I thought you said earlier that as long as I use an image file the DMM would not work properly since it will allocated full-memory scale during startup?

And how would Smart Image and Delay Load make DMM work with an image file?

As earlier we mainly focus on the DMM feature itself, I didn't introduce other options for simplicity.

Smart Image: because it only stores valid disk sectors, during startup loading, only valid data is copied to the ramdisk.
Delay Load: the image file data is loaded to the ramdisk only when needed (first read request), so it can work with DMM.

Remember that DMM is a feature which allocates memory on demand. That means if there's no read/write requests to the ramdisk, there will be no memory allocation caused.